This invention pertains to a servo-release for automatic firearms, in particular a machine cannon.
Automatic firearms generally include a servo-release which, by means of an as small as possibly externally applied force, brings about a release of a breech body for firing, which reciprocally moves forwardly and rearwardly along a defined path. The reciprocal movement of the breech body serves to fire the weapon and to catch the breech body for purposes of interrupting the firing. In view of the necessary features for an automatic firearm, for example multiple application, high firing force, ease of manipulation, reliability, minimal malfunctioning and safety, the servo-release is of particular significance.
There is, for example, described in German published patent application No. 14 539 10 a servo-release of the aforedescribed known type, with which a firing of the breech body in the catch position can be attained without the use of servo-braking parts and wherein a release is accomplished which only requires a reduced force. There is mounted between one element, which gives up its recoil energy as auxiliary energy (in this case a breech block) and a storage spring for the auxiliary energy, on the one hand, as well as, on the other hand, between the storage spring and a catch lever actuated by the stored auxiliary energy, a plurality of partially spring biased levers. This known servo-release has a large number of individual interacting parts which is, with respect to the manufacture of these parts, their mounting and the spatial requirements in the weapon a significant drawback. In view of the complexity of this known construction there occur an inordinately high number of disadvantageous malfunctions which influence negatively the efficiency, reliability and availability of this type of known weapon. Furthermore, the servo-release of this known weapon does not make possible a sufficient storage possibility for purposes of avoiding unintentional firing, for example during impact blows during the transporting of the weapon, so that obvious safety requirements are not sufficiently fulfilled.
There is also already known a servo-release having comparatively a lower number of individual parts which also occupy a smaller space, and such a known servo-release is, for example, disclosed in German published application 23 53 870. However, this known servo-release also has some distinct drawbacks which negatively influence the functional safety of the weapon in a very sensitive manner. It includes a storage spring adapted to be biased by the recoiling breech block body which acts as a return positioning means for a control arrangement for pivoting a catch lever. The catch lever is loaded by a strong spring which repositions the catch cam into the firing position. Although the control arrangement for actuating the catch lever for firing requires only a reduced to be introduced force, it must, however, overcome the strong return positioning force of the afore-mentioned spring from interrupting the firing force. Additionally, the control arrangement forming the operative chain of the weapon does not provide a continuously reliable obligatory effect. Thus, it surrounds an element for taking off the auxiliary energy from the recoiling breech block body and a transfer element for biasing the storage spring. The extracting element grips, in opposition to a deflectable spring force into the path of movement of the breech body and is coupled via a further spring with the transfer element. A rupture of the last-mentioned spring during continuous firing causes the significant drawback of an unintentional continuance of firing.
In both of these known servo-release mechanisms there is built-in an individual arrangement for selecting the mode of firing (individual or continuous firing). This results disadvantageously in a further complication of the construction and thereby, in addition to the corresponding spatial requirements, to an increased servicing requirement and an increased malfunctioning frequency of an automatic firearm having the afore-described servo-release mechanism.